Add support for setting seccomp profile and allow privilege escalatio…

[tspearconquest]

…n security context values

This adds support for 2 new configuration options to control the injected container's security context:

      WEBHOOK_CONTAINER_SECURITY_CONTEXT_ALLOW_PRIVILEGE_ESCALATION: "false"
      WEBHOOK_CONTAINER_SECURITY_CONTEXT_SECCOMP_RUNTIME_DEFAULT: "true"

Both of these are optional settings. The first; if defined, adds the allowPrivilegeEscalation field to the securityContext spec of the initContainer. The second; if defined, and set true, adds the seccompProfile field to the securityContext spec of the initContainer with type: runtime/default value pre-defined.

[181192]

Thanks @tspearconquest ☺️